Hot Rod Forum banner

4.3 question

739 Views 3 Replies 3 Participants Last post by  fast68
What is the shaft in the lifter valley called and what is it for? A buddy stopped buy with his block so I could help him get a bolt out and I've never see the insides of a 4.3 before. It looks like some type of balancing shaft. Can someone please educate me.
1 - 4 of 4 Posts
About mid nineties a "balance shaft" was added to the 4.3. V-6 engines tend to be unbalanced "shakers". These wern't bad, but GM wanted a smoother engine. They imitated what a few foreign builders were doing and added the balance shaft. It's function is to shake the engine internally in the opposite direction of the engines natural harmonics. Thus canceling the vibrations out at certain rpms. Usually at cruising speed.
Thanks for the info, I thought maybe thats what it was just never seen one.
macomb, i used to live there years ago.

92 was first year for the balance shaft

my 91 doesnt have one

my brother had a 92

ive worked on tons of these 4.3 engines

love em

always run strong and forever

have over 300k on one in one of the work astro vans

197k on mine

a little more was on the 92 still running great

good luck
See less See more
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.